This study will evaluate the effects of GM-CSF over a dose range on human monocyte/macrophage activation, as measured by monocyte/macrophage cytotoxicity, monocyte TNF release, interferon-gamma induction, monocyte IL-1 induction, monocyte TNF release, interferon-gamma induction, monocyte IL-1 induction, monocyte DR and Fc expression, and interferonbeta2 mRNA induction in monocytes/macrophages and lymphocyte phenotypes. It will also determine the toxicity of GM-CSF administered to patients with cancer. GRANT M01RR000960286 The objects of this study are to determine the survival rate and the disease-free survival rate for patients with glioblastomamultiforsme treated to one of six total dose levels delivered at 1.20Gy b.i.d; to determine normal tissue tolerance to hyperfraction delivered at 1.20 Gy b.i.d. with 4-8 h between fractions delivered the same day, to total doses of 64.80 Gy/54 Fx, 72.00 Gy/60 Fx, and 76.80 Gy/64 Fx.